Should be fair to refund customer.
If unit was received is different as they will warrant a replacement for anything defective.
Tell that to Bitmain.
If UPS loses a delivery, how do they reimburse Bitmain? I guess it depends on how Bitmain insures the shipment, if at all. I know they send via UPS World Saver but I'm sure insurance is optional. Does UPS have an automatic minimum insurance included??? I don't know.
Let this this a cautionary tale to you all. If and when UPS loses your miner package, you are SOL in terms of getting your btc back. Even Bitmain doesn't play fair when it comes to it.